The public service broadcaster committed a "major breach" of industry standards by not revealing that the narrator of a documentary about the Gaza conflict was the child of a Hamas official, as determined by regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The head of the BBC had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
The authority has ordered the BBC to broadcast a evening announcement about its conclusions.
"Given this constitutes a serious breach of our code, we are ordering the corporation to broadcast a message of our conclusions against it on BBC Two at 21:00, with a timing to be determined," the statement read.
'Potential to Damage Trust'
The regulator's report stated: "Our probe concluded that the film's failure to disclose that the presenter's father held a position in the Hamas-administered government was materially misleading.
"This implied that the audience did not have vital facts which may have been highly relevant to their assessment of the narrator and the information he presented.
"Trust is at the core of the relationship between a television network and its audience, especially for a national broadcasting corporation such as the BBC.
"This error had the potential to undermine the exceptionally strong levels of trust that audiences would have placed in a documentary produced by the BBC about the conflict in Gaza."
The programme was pulled from the BBC's streaming service in February after the boy's family links came to light, and in this past July an corporation's own inquiry determined it infringed the broadcaster's editorial guidelines on truthfulness.
A corporation official commented: "The regulator's decision is in agreement with the conclusions of the corporation's inquiry, that there was a serious error in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept the authority's determination in full. We will adhere to the directive as soon as the date and language are finalised."
